mmc: stop abusing the request queue_lock pointer

Replace the lock in mmc_blk_data that is only used through a pointer
in struct mmc_queue and to protect fields in that structure with
an actual lock in struct mmc_queue.

Suggested-by: Ulf Hansson <[e-mail]>
Reviewed-by: Ulf Hansson <[e-mail]>
Signed-off-by: Christoph Hellwig <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/mmc/core/block.c

···
  * There is one mmc_blk_data per slot.
  */
 struct mmc_blk_data {
-	spinlock_t	lock;
 	struct device	*parent;
 	struct gendisk	*disk;
 	struct mmc_queue queue;
···
 		blk_mq_end_request(req, BLK_STS_OK);
 	}
 
-	spin_lock_irqsave(mq->lock, flags);
+	spin_lock_irqsave(&mq->lock, flags);
 
 	mq->in_flight[mmc_issue_type(mq, req)] -= 1;
 
···
 
 	mmc_cqe_check_busy(mq);
 
-	spin_unlock_irqrestore(mq->lock, flags);
+	spin_unlock_irqrestore(&mq->lock, flags);
 
 	if (!mq->cqe_busy)
 		blk_mq_run_hw_queues(q, true);
···
 	unsigned long flags;
 	bool put_card;
 
-	spin_lock_irqsave(mq->lock, flags);
+	spin_lock_irqsave(&mq->lock, flags);
 
 	mq->in_flight[mmc_issue_type(mq, req)] -= 1;
 
 	put_card = (mmc_tot_in_flight(mq) == 0);
 
-	spin_unlock_irqrestore(mq->lock, flags);
+	spin_unlock_irqrestore(&mq->lock, flags);
 
 	if (put_card)
 		mmc_put_card(mq->card, &mq->ctx);
···
 		 * request does not need to wait (although it does need to
 		 * complete complete_req first).
 		 */
-		spin_lock_irqsave(mq->lock, flags);
+		spin_lock_irqsave(&mq->lock, flags);
 		mq->complete_req = req;
 		mq->rw_wait = false;
 		waiting = mq->waiting;
-		spin_unlock_irqrestore(mq->lock, flags);
+		spin_unlock_irqrestore(&mq->lock, flags);
 
 		/*
 		 * If 'waiting' then the waiting task will complete this
···
 	/* Take the recovery path for errors or urgent background operations */
 	if (mmc_blk_rq_error(&mqrq->brq) ||
 	    mmc_blk_urgent_bkops_needed(mq, mqrq)) {
-		spin_lock_irqsave(mq->lock, flags);
+		spin_lock_irqsave(&mq->lock, flags);
 		mq->recovery_needed = true;
 		mq->recovery_req = req;
-		spin_unlock_irqrestore(mq->lock, flags);
+		spin_unlock_irqrestore(&mq->lock, flags);
 		wake_up(&mq->wait);
 		schedule_work(&mq->recovery_work);
 		return;
···
 	 * Wait while there is another request in progress, but not if recovery
 	 * is needed. Also indicate whether there is a request waiting to start.
 	 */
-	spin_lock_irqsave(mq->lock, flags);
+	spin_lock_irqsave(&mq->lock, flags);
 	if (mq->recovery_needed) {
 		*err = -EBUSY;
 		done = true;
···
 		done = !mq->rw_wait;
 	}
 	mq->waiting = !done;
-	spin_unlock_irqrestore(mq->lock, flags);
+	spin_unlock_irqrestore(&mq->lock, flags);
 
 	return done;
 }
···
 		goto err_kfree;
 	}
 
-	spin_lock_init(&md->lock);
 	INIT_LIST_HEAD(&md->part);
 	INIT_LIST_HEAD(&md->rpmbs);
 	md->usage = 1;
 
-	ret = mmc_init_queue(&md->queue, card, &md->lock);
+	ret = mmc_init_queue(&md->queue, card);
 	if (ret)
 		goto err_putdisk;
 

drivers/mmc/core/queue.c

···
 	struct mmc_queue *mq = q->queuedata;
 	unsigned long flags;
 
-	spin_lock_irqsave(mq->lock, flags);
+	spin_lock_irqsave(&mq->lock, flags);
 	__mmc_cqe_recovery_notifier(mq);
-	spin_unlock_irqrestore(mq->lock, flags);
+	spin_unlock_irqrestore(&mq->lock, flags);
 }
 
 static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req)
···
 	unsigned long flags;
 	int ret;
 
-	spin_lock_irqsave(mq->lock, flags);
+	spin_lock_irqsave(&mq->lock, flags);
 
 	if (mq->recovery_needed || !mq->use_cqe)
 		ret = BLK_EH_RESET_TIMER;
 	else
 		ret = mmc_cqe_timed_out(req);
 
-	spin_unlock_irqrestore(mq->lock, flags);
+	spin_unlock_irqrestore(&mq->lock, flags);
 
 	return ret;
 }
···
 
 	mq->in_recovery = false;
 
-	spin_lock_irq(mq->lock);
+	spin_lock_irq(&mq->lock);
 	mq->recovery_needed = false;
-	spin_unlock_irq(mq->lock);
+	spin_unlock_irq(&mq->lock);
 
 	mmc_put_card(mq->card, &mq->ctx);
 
···
 
 	issue_type = mmc_issue_type(mq, req);
 
-	spin_lock_irq(mq->lock);
+	spin_lock_irq(&mq->lock);
 
 	if (mq->recovery_needed || mq->busy) {
-		spin_unlock_irq(mq->lock);
+		spin_unlock_irq(&mq->lock);
 		return BLK_STS_RESOURCE;
 	}
 
···
 	case MMC_ISSUE_DCMD:
 		if (mmc_cqe_dcmd_busy(mq)) {
 			mq->cqe_busy |= MMC_CQE_DCMD_BUSY;
-			spin_unlock_irq(mq->lock);
+			spin_unlock_irq(&mq->lock);
 			return BLK_STS_RESOURCE;
 		}
 		break;
···
 	get_card = (mmc_tot_in_flight(mq) == 1);
 	cqe_retune_ok = (mmc_cqe_qcnt(mq) == 1);
 
-	spin_unlock_irq(mq->lock);
+	spin_unlock_irq(&mq->lock);
 
 	if (!(req->rq_flags & RQF_DONTPREP)) {
 		req_to_mmc_queue_req(req)->retries = 0;
···
 	if (issued != MMC_REQ_STARTED) {
 		bool put_card = false;
 
-		spin_lock_irq(mq->lock);
+		spin_lock_irq(&mq->lock);
 		mq->in_flight[issue_type] -= 1;
 		if (mmc_tot_in_flight(mq) == 0)
 			put_card = true;
 		mq->busy = false;
-		spin_unlock_irq(mq->lock);
+		spin_unlock_irq(&mq->lock);
 		if (put_card)
 			mmc_put_card(card, &mq->ctx);
 	} else {
···
  * mmc_init_queue - initialise a queue structure.
  * @mq: mmc queue
  * @card: mmc card to attach this queue
- * @lock: queue lock
  *
  * Initialise a MMC card request queue.
  */
-int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
-		   spinlock_t *lock)
+int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card)
 {
 	struct mmc_host *host = card->host;
 	int ret;
 
 	mq->card = card;
-	mq->lock = lock;
 	mq->use_cqe = host->cqe_enabled;
+	
+	spin_lock_init(&mq->lock);
 
 	memset(&mq->tag_set, 0, sizeof(mq->tag_set));
 	mq->tag_set.ops = &mmc_mq_ops;

drivers/mmc/core/queue.h

···
 
 struct mmc_queue {
 	struct mmc_card		*card;
-	spinlock_t		*lock;
 	struct mmc_ctx		ctx;
 	struct blk_mq_tag_set	tag_set;
 	struct mmc_blk_data	*blkdata;
 	struct request_queue	*queue;
+	spinlock_t		lock;
 	int			in_flight[MMC_ISSUE_MAX];
 	unsigned int		cqe_busy;
 #define MMC_CQE_DCMD_BUSY	BIT(0)
···
 	struct work_struct	complete_work;
 };
 
-extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *);
+extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *);
 extern void mmc_cleanup_queue(struct mmc_queue *);
 extern void mmc_queue_suspend(struct mmc_queue *);
 extern void mmc_queue_resume(struct mmc_queue *);